In many traffic scenarios encountered in urban locations, for example in city traffic, distances between moving and stationary objects in the rear of a vehicle are often relatively short, for example a few meters. Drivers of vehicles in such scenarios are confronted with complex situations in which the drivers are susceptible to being momentarily distracted. A momentary distraction can, for example, result in one or more collisions when traveling in a forward direction or while being stationary in a traffic situation. Such collisions may cause vehicle occupants to suffer “whiplash” type injuries. The term “whiplash injury” is understood to mean an injury sustained by the sudden acceleration or deceleration of a vehicle occupant during a collision event. The rapid, unanticipated movement of the occupant during such a collision event may cause severe soft or hard tissue injury to an occupant's neck and/or back resulting in the condition commonly known as whiplash.
As stated in NHTSA DOT HS 809 540 report dated March 2003 by Satokh Singh, PhD entitled “Driver Attributes and Rear End Crash Involvement Propensity”, rear end crash refers to a crash in which the front of one vehicle collides with the rear of another vehicle. Thus, a driver in such a crash may be the driver of a striking vehicle, a struck vehicle or of the vehicle that is both striking and was struck. Rear end crashes are not only one of the most frequently occurring types of crashes, but also are responsible for a large number of injuries and fatalities and substantial property damage every year. In fact, based upon the General Estimates System (GES) of the National Automotive Sampling System (NASS) and the Fatality Analysis Reporting System (FARS) data, complied by the National Highway Transportation Safety Agency (NHTSA), approximately 29.7% of all crashes in the year 2000 were rear-end crashes. These crashes were responsible for 30% of all injuries and 29.7% of the property damage. So far as the involvement of drivers in rear-end crashes is concerned, of the 190,625,000 licensed drivers (Federal Highway Administration (FHWA)) in 2000, approximately 2.2% were involved in rear-end crashes. Further, of the 6% of the licensed drivers involved in all types of crashes, 36% were involved in rear end crashes alone.
This significant involvement of drivers in rear end crashes alone is a matter of great concern. It is becoming increasingly apparent that in order to develop effective rear end crash countermeasures, a better understanding of the driving behavior and performance associated with response to driving conflict or imminent crash situations is needed. In addition, improved safety countermeasures during a pre-crash phase are especially needed to protect occupants from injuries.
NHTSA has funded extensive research on rear end collision warning and control. Radar, lidar, ultrasonic and vision based systems installed on the front of impacting or bullet vehicles have some effect on reducing front to rear end crashes between vehicles. Some lidar and radar systems installed at the back of a vehicle being impacted to predict unavoidable collisions and activate appropriate countermeasures to reduce vehicle occupant injuries such as neck whiplash are also known in the literature.
There is thus a requirement for increased vehicular collision management, especially in city and urban situations, and most especially for rear end collision to provide a low cost whiplash reduction system for occupants in vehicles that are struck from the rear.